Removal of COD and TOC From Petroleum Synthetic Wastewater Containing Cyclic Aromatic Hydrocarbons Using the Photo-Fenton Process by the Box-Behnken Method

Background: In the last few decades, concern over environmental safety has increased significantly. One of the main causes of environmental degradation is the discharge of untreated pollutants into water bodies. This study examined the efficiency of the photo-Fenton oxidation process to remove chemical oxygen demand (COD) and total organic carbon (TOC) from petroleum wastewater.Methods: Experiments were designed using the Box-Behnken method- a model of the response surface method (RSM) by MINITAB software. First, a wooden chamber equipped with UV lamps installed in the center was applied. The effect of effective parameters on the photo-Fenton process, including naphthalene concentration (۱۰-۷۰ μg/L), pH (۲-۷), H۲O۲ (۵۰-۸۰۰ mg/L), Fe (۵-۸۰ mg/L), contact time (۱۰-۱۲۰ minutes) and UV rays was investigated.Results: The highest removal efficiency of the COD (case ۸۹.۲۷) was at achieved at pH = ۲, UV = ۲۴, naphthalene concentration ۱۰ μg/L, Fe concentration ۳۶.۰۶ mg/L, hydrogen peroxide content ۸۰۰ mg/L, and contact time ۱۲۰ min. Besides, the highest removal efficiency of the process in removing TOC was ۷۱.۰۴% obtained at ۲ pH = ۲۴, UV = ۲۴, and a reaction time of ۱۲۰ min.Conclusion: Based on the results of this research, the photo-Fenton process has a significant efficiency in removing COD and TOC from petroleum effluents containing cyclic aromatic hydrocarbons and can be utilized as an efficient method for the treatment of petroleum wastewaters.

Keywords:

Naphthalene , Advanced Oxidation Process , COD , TOC , Photo-Fenton , petroleum effluent